These days, speedlights are popular as ever, partly because, unlike studio strobes, speedlights are battery operated. AA batteries are the most common power source used in hot-shoe flashes. Good quality AA batteries, like Eneloop or Powerex, do the job well in many cases. However, quite often, faster recycling times and longer continuous operation time of a speedlight (without swapping the batteries) are required. For example, at events like wedding, being ready any second to take a picture (or even a sequence of pictures) can be critical for catching that once-in-a-lifetime moment. That's when external power packs come into the picture. In this review, we are taking a close look at Nissin PS 8 Power Pack.

Nissin PS 8 Power Pack looks and feels very solid. From the knobs and cables to the body itself, the quality of the materials and assembly is top-notch.

Most external parts of Nissin PS 8 are plastic, but the belt clip is metal, so we had no problem trusting it. PS 8 weighs just over 1.5 pounds (710g), which is relatively heavy, but the unit is quite compact and comfortable to use whether you put it on the included shoulder strap or clip to your belt.

Nissin PS 8 Power Pack has two power sockets and can power 1 or 2 speedlights at the same time. However, only one power cable is included, so you would need to purchase an extra one to connect two speedlights.

The power switch has 4 positions: OFF, LOW, MEDIUM, and HIGH. The higher power settings mean faster recycling times, but they also stress the battery more. If you need the maximum performance, use the HIGH setting. If slightly slower recycling times are acceptable for your photoshoot, select MEDIUM or LOW power options to go easier on the battery and extend its life. According to our measurements, a single flash recycling on MEDIUM is about 20-30% slower, and LOW setting can slow the recycling down by around 60%, which is still 2+ times faster compared to AA batteries.

Nissin specifies the flash recycling time to be between 0.5 and 0.7 seconds at full power. This varies depending on the flash you use, because some flashes can recycle faster than others. With our Canon version of Nissin PS 8, we tested a few flashes and found that Canon 580EX II and Nissin Di700 recycle at 0.7 seconds (at the HIGH setting), Nissin Di866 II and LumoPro LP180 take about 1 second, and Nissin MG8000 Extreme recycling time is close to 1.5 seconds. For all flashes, the recycling time with Nissin PS 8 was 4 times faster than with AA batteries.

Nissin PS 8 Power Pack is capable of delivering about 550 full power flashes on a single battery charge. The unit has a built-in battery level indicator. When the charge level is below 30%, the indicator turns from green to red. During our testing, we noticed that when the indicators switched to red, the recycling slowed down to a level equivalent to the LOW power output setting.

The PS 8 battery is made as a replaceable cartridge. It is extremely easy to pop it out: you simply open the security lock and pull the lever on the side of the unit. We really like this design because it allows you to quickly replace the battery (if you have a spare one) to continue shooting. The battery itself can be plugged into a wall outlet for re-charging. Nissin promises that the battery can be charged/discharged about 500 times, which we have yet to confirm :).

Another neat feature of Nissin PS 8 is the USB port. In the today's world of gadgets, it can be quite handy to have an emergency charging option for your smartphone or tablet. In our tests, we were able to fully charge iPhone 5 two times on a single battery charge of PS 8 (in about 2 hours each time).

It is also worth mentioning that Nissin PS 8 gives you a peace of mind by having a built-in overheating protection. If, for any reasons, the unit overheats, it will turn itself off and then resume the operation automatically after sufficiently cooling down. We have not experienced any overheating issues and can only guess that this is possible when working in a very hot climate or pushing the pack to the extreme, for example, by continuously firing hundreds of shots at full power. (However, in that case, your flash is way more likely to shut down due to its own overheating.)

Finally, we want to add that Nissin PS 8 Power Pack comes with a rainproof case, which can be very important for some outdoor applications. Obviously, you need to make sure that your flashes and the camera are also weatherproof.

To conclude, Nissin PS 8 is a high-quality external power pack that is well-designed and can power up to 2 of your speedlights simultaneously. Compared to AA batteries, it speeds up the recycling times about 4 times. The quick release mechanism allows you effortlessly take the battery out for charging or swapping with a new one. The built-in USB socket can save the day, should you ever need an emergency charge for some of your USB devices. After using Nissin PS 8 Power Pack for quite some time, we have no hesitation recommending it.